## CryptoDB

### Paper: Commitment Capacity of Discrete Memoryless Channels

Authors: Andreas Winter Anderson C. A. Nascimento Hideki Imai URL: http://eprint.iacr.org/2003/165 Search ePrint Search Google In extension of the bit commitment task and following work initiated by Crepeau and Kilian, we introduce and solve the problem of characterising the optimal rate at which a discrete memoryless channel can be used for bit commitment. It turns out that the answer is very intuitive: it is the maximum equivocation of the channel (after removing trivial redundancy), even when unlimited noiseless bidirectional side communication is allowed. By a well-known reduction, this result provides a lower bound on the channel's capacity for implementing coin tossing, which we conjecture to be an equality. The method of proving this relates the problem to Wyner's wire--tap channel in an amusing way. We also discuss extensions to quantum channels.
##### BibTeX
@misc{eprint-2003-11879,
title={Commitment Capacity of Discrete Memoryless Channels},
booktitle={IACR Eprint archive},
keywords={foundations / Commitment Schemes, Information Theory, Noisy Channels},
url={http://eprint.iacr.org/2003/165},
note={ anderson@imailab.iis.u-tokyo.ac.jp 12275 received 11 Aug 2003},
author={Andreas Winter and Anderson C. A. Nascimento and Hideki Imai},
year=2003
}